Driving 6 ohm speakers
Driving 6 ohm speakers
I have a pair of Denon hifi speakers which are rated at "6 ohms". All the amps I have ever looked at seem to drive external devices at either 4 ohms or 8 ohms; nobody seems to do exactly 6 ohms. So which setting will give me the best result : 4 ohms or 8 ohms?
Re: Driving 6 ohm speakers
Solid-state amps don't usually have a 'setting', they just cope. Valve amps might have a setting... in which case try both options and see which works best.
The impedance value on the speaker is entirely nominal and the actual impedance varies substantially over the frequency range. A nominally 6 Ohm speaker can easily go down as low as 2 or 3 Ohms at low frequencies, rising to 15 or 20 Ohms around the crossover frequency, and maybe peak at 30 or 40 Ohms at the bass driver's resonant frequency. EG:
The impedance value on the speaker is entirely nominal and the actual impedance varies substantially over the frequency range. A nominally 6 Ohm speaker can easily go down as low as 2 or 3 Ohms at low frequencies, rising to 15 or 20 Ohms around the crossover frequency, and maybe peak at 30 or 40 Ohms at the bass driver's resonant frequency. EG:
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- Hugh Robjohns
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Re: Driving 6 ohm speakers
never heard of 6 ohm ones before, but with a decent quality amp I'd go for 8 Ohm setting, unless it's a valve amp, in which case I would cautiously suggest 4 ohm.
My reasoning is as follows:
A solid state amp won't have any issues with not being fully loaded, and is likely to have more output capability than the speakers can handle anyway.
A valve amp doesn't usually suffer much of feeding speakers that are lower impedance than ideal, but can suffer excessive voltage swings if loaded too light.
My reasoning is as follows:
A solid state amp won't have any issues with not being fully loaded, and is likely to have more output capability than the speakers can handle anyway.
A valve amp doesn't usually suffer much of feeding speakers that are lower impedance than ideal, but can suffer excessive voltage swings if loaded too light.
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Re: Driving 6 ohm speakers
I've come across it quite often, most recently in the PMC Prophecy 1 speakers I helped a friend install a few weeks back which are nominal 6 Ohm designs.
https://pmc-speakers.com/home-audio/prophecy/prophecy1/
https://pmc-speakers.com/home-audio/prophecy/prophecy1/
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- Hugh Robjohns
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Posts: 43693 Joined: Fri Jul 25, 2003 12:00 am
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(But generally posting my own personal views and not necessarily those of SOS, the company or the magazine!)
In my world, things get less strange when I read the manual...
(But generally posting my own personal views and not necessarily those of SOS, the company or the magazine!)
In my world, things get less strange when I read the manual...
Re: Driving 6 ohm speakers
A lot of surround sound speakers seem to be either 4 or 6 ohms. Means they can get away with lower powered amps in A/V systems, important when you are packing five channels or more in a fairly small package.
The Yamaha 7.1 A/V amp I inherited with the new house had an 8 ohm or 6 ohm setting for the speakers.
The system speakers were 6 ohm so the amp was set to 6 ohm.
No idea what the ohmage setting did but the system (rather mismatched with £100 a pair L+R front speakers and a £650 centre speaker) didn’t sound good so it’s now been replaced by an Atmos soundbar.
The Yamaha 7.1 A/V amp I inherited with the new house had an 8 ohm or 6 ohm setting for the speakers.
The system speakers were 6 ohm so the amp was set to 6 ohm.
No idea what the ohmage setting did but the system (rather mismatched with £100 a pair L+R front speakers and a £650 centre speaker) didn’t sound good so it’s now been replaced by an Atmos soundbar.
Reliably fallible.
Re: Driving 6 ohm speakers
I seem to recall reading somewhere years ago that the optimum design load for solid state amps was close to 6 Ohms than 4 or 8?
A very few solid state amps will carry a warning that the speakers must not be less than 8 Ohms but it would be a pretty poor design IMHO if it could not safely cope with 6R?
A hi fi valve amp should not mind a 6 Ohm load on an 8R tap but as Hugh says, try 4 if available. For a valve guitar amp stay with an 8 Ohm tap because that is very slightly safer than 4 in terms of valve arcing under overdrive.
In all cases, 'size matters' size of signal that is. If none of the amps are driven close to clipping they will be perfectly safe (unless very crap designs!)
Dave.
A very few solid state amps will carry a warning that the speakers must not be less than 8 Ohms but it would be a pretty poor design IMHO if it could not safely cope with 6R?
A hi fi valve amp should not mind a 6 Ohm load on an 8R tap but as Hugh says, try 4 if available. For a valve guitar amp stay with an 8 Ohm tap because that is very slightly safer than 4 in terms of valve arcing under overdrive.
In all cases, 'size matters' size of signal that is. If none of the amps are driven close to clipping they will be perfectly safe (unless very crap designs!)
Dave.